1. Field of the Invention
The present invention relates to a connection structure for an electric wire and a terminal.
2. Description of the Related Art
Conventionally, signal lines and power lines in which an electric wire having a conductor made of a copper material and a terminal made of a copper material are connected to each other have been used in automobiles, consumer electronics products, etc.
On the other hand, in the automobile industry, to reduce influences on the environment, it is an important matter to increase the fuel efficiency by reducing the weight of vehicles. To this end, electric wires which employ, as a material of the conductor, aluminum which is lighter than copper are attracting much attention.
However, such electric wires are associated with a problem that aluminum is prone to corrosion under the presence of water and copper ions and hence they tend to corrode if water enters the connection portion of the aluminum conductor and the copper terminal.
In view of the above, a connection structure for an electric wire and a terminal has been proposed which prevents corrosion by preventing entrance of water by covering a connection portion of an aluminum conductor and a copper terminal with a heat-shrinkable tube (Refer to JP-A-2010-165630).
In the connection structure for the electric wire and the terminal disclosed in JP-A-2010-165630, an electric wire having a conductor covered with a covering member is connected to a connector terminal having an intermediate connection portion between a contact portion and a wire barrel portion. The connection structure for the electric wire and the terminal has a conductor connection portion in which the conductor is fastened to the wire barrel portion. The conductor connection portion is covered with a waterproof tube which is a heat-shrinkable tube. The intermediate connection portion and its neighborhood are covered with a terminal-side end portion of the waterproof tube without interstices.
However, there are a wide variety of terminal shapes. There may be terminals each of which is shaped so as to be difficult to cover with a hollow covering member such as a heat-shrinkable tube so that it is in close contact with the outer surfaces of the terminal. With such terminals, the waterproof performance may become low.